1. Field of the Invention
The present invention relates to the field of artillery breech wedges, and more particularly those of the type including means to support a primer-cartridge magazine that is driven in translation and rotation by a rack and pinion assembly.
2. Description of the Prior Art
Such breech wedges are used in cannons that fire ammunition comprising a projectile and a propulsive charge, contained either in a power bag or a combustible shell. The charge is fired by a primer placed in a chamber in the rear of the breech wedge and communicating through a straight, narrow channel with the propulsive charge placed in the breech opening. To increase the firing rate, the primers are mounted on revolving magazines that bring a new unspent primer into the chamber with each shot fired.
The French patent No. 2.464.451 describes a breech wedge of the type mentioned above. The rack and pinion assembly is actuated by a lever integral with the pinion and a cam integral with the weapon recoil slides. Also in this document, the pin is carried on a slider that slides on the breech wedge, butting up against the sleeve in the firing position, or releasing the primer-cartridge magazine when open, with a set of grooves arranged in a tee and inclined with respect to the direction of motion of the wedge. Lastly, the narrow channel is inclined and is relatively long and does not reach the center of the firing plate.
The breech wedge of FR '451 will now be explained in greater detail.
In FIG. 7, the axis XX' of the gun tube of FR '451 has been represented, as well as the chock of the breech 1 and a part of the handle of this breech in which the chock slides on surfaces 53a and 53b which are visible in the figure. Perforations 54 with axis YY', which is called the ignition conduit, is provided in the breech chock 51. This pipe opens at one end of the firing breech of gun 55 and at the other extremity towards the detonator breech 56.
The device according to FR '451 detonator support 57 with a circular form, as represented in detail in FIG. 10, which holds n detonators 58. The number of detonators, in this particular example of implementation has been selected to be equal to 12 for reasons of available space. It is naturally clear that this number can be increased or reduced on the basis of the available space to house the device in the breech. Detonators 58 are mounted on the detonator support in such a manner that their axes are parallel with the YY' axis of ignition conduit 54, with one detonator being located in the detonator chock 56, while the others are placed in housing 9 provided in the breech chock. During a change of detonator, the detonator support must be able to rotate so as to bring an unfired detonator into the detonator breech. To achieve this, the detonator support must perform a stepwise rotational movement around axis ZZ' which is parallel to the ignition conduit. This stepwise rotation occurs during the translational motion of the detonator support along the axis ZZ', which is achieved by the couple comprising striking pin 60 with axis 60a and rack 61. Rotation is achieved when the detonators have left housings 59 and breech 56. The rack can slide along axis ZZ', it is an integral part of detonator support 57, and it is activated by a striking pin 60 which is an integral part of lever 62 controlled during the opening of the gun breech .Rack 61 is a circular rack used to permit the simultaneous rotational and translational motion of the detonator-support.
The rotational motion of the detonator-support of FR '541 is achieved by grooves 63a and 63b provided in shaft 64 (represented in FIGS. 11 and 12) which work in cooperation with grooves 65 of grooved ring 66 (represented in FIGS. 13 and 14). The grooved shaft possesses, along its generating lines, two assemblies 63a and 63b of male grooves, which two assemblies are separated by a distance D and shifted by .pi./n. The number of grooves of the two assemblies must be equal to the number of detonators placed on the detonator-support. These grooves are fitted with bevels 67a and 67b with an angel .alpha. with respect to the generating lines of the shaft, and forming between themselves an angle of (.pi.-2.alpha.). The grooved ring comprises n female grooves 68 (represented in FIG. 14) which can slide along the male grooves 63a or 63b of shaft 64. The height of the ring is slightly larger than the distance D, so that the shaft is always engaged on the ring. The extremities of the male grooves 65 formed between the female grooves of the ring are fitted with bevels 69 at the same angle .alpha. as those provided on the shaft, and forming between themselves an angle of (.pi.-2.alpha.).
The grooved ring 66 of FR '451 is integrally connected to the breech chock by nut 70 and tongue 71 held in groove 73 of the breech chock.
The detonator-support of FR '451, as shown in FIG. 10, consists of two disk-shaped parts 74 and 75, which are integrally connected by screw 76 and positioning pin 77. The back bottoms 78 of the detonators are held between the two parts 74 and 75. The assembly formed in this manner is integrally connected to grooved shaft 64 through the intermediary of a plug 79, for example, with a hexagonal shape, and by pin 80. One variant of FR '451 consists in immersing the bottoms of the detonators in a block, for example, made of plastic material, whose function is to replace parts 74 and 75, as well as screw 76 and finger pin 77. In both cases, the detonator-support assembly constitutes a means which can easily be disassembled and which permits the rapid change of detonator-supports.
Disk-shaped part 74 of FR '451 also comprises holes 81 which are aligned with the axes of the detonators and which permit the passage of the striking pin 82 which is housed in the striking pin support breech 83, and which also rests against surface 85 of the detonator-support when the breech chock is closed. The striking pin 82 is kept in the retracted position by spring 86 which is kept in place by screw 87 and activated at the appropriate time by an adjoining device which is not represented because it can be easily imagined by the expert.
The detonator-support chock 83 of FR '451 is maintained on the breech chock by a set of slide guides 88 and it is subjected to the action of spring 89, which is limited by abutment 90 attached to the breech chock. A second set of slide guides 91a and 91b, placed on the striking pin support breech and the breech ring, respectively, allows the striking pin support breech to disengage the detonator-support in order to permit its recoil movement. After completion of a pathway, slide guides 91a and 91b are uncoupled, with the striking pin support breech is now kept against abutment 90 (see FIG. 8).
The operation of the device according to FR '451 is described below. The breech chock i closed (see FIG. 7), the striking pin 82 is activated and it ignites detonators 58 which, through the intermediary of channel 54, ignites the ammunition placed in chock 55 of the gun. After firing, the breech chock is opened (see FIG. 8); the striking pin support breech is entrained by its slide guides 91a and it disengages the detonator-support. During this phase, lever 62 is automatically activated and it entrains pin 60 as well as circular rack 61 and shaft 6 which moves in grooved ring 66. At a predetermined position, bevels 68b and 69 come in contact (see FIG. 16) and they rotate shaft 64 by .pi./n. Next, the new ammunition is placed in the gun breech and the breech chock is closed. At the same time, lever 62 is activated, bevels 67a and 69 come in contact (see FIG. 15), and rotate the shaft by .pi./n. The total rotation of 2.pi./n achieved thus has permitted the placing of a new detonator in position. The striking pin support breech is placed in a position on the detonator-support and a new spot can be fired.
Although this breech wedge is generally satisfactory, it does have certain disadvantages. Firstly, there are many moving parts and the slider sliding system calls for delicate machining. Also, the asymmetrical ignition generates pressure peaks that cause ballistic dispersion.
The present invention aims to remedy these disadvantages by providing a breech wedge in which the magazine movements are controlled directly by the translational motion of the wedge, without requiring any external mechanical parts. The invention also attempts to simplify the primer securing and firing mechanism.